Aeroplane.



C. RVCLAPP.

AEROFLANE.

APPLICATION FILED AUGJG, 1911.

Patented 00$. 19, 1915.

3 SHEETS-SHEET 1.

WITNESSES In him 5 0 INVENTOR I ATTORNEYS C. R. CLAPP.

AEROPLANE.

Patented Oct. 19, 1915.

a INVENTOR W C. R. CLAPP.

AEROPLANE.

APPLICATION r1150 Aue.1s. 1911..

Patented 001:. 19, 1915.

3 SHEETS-SHEET 3.

CHARLES RUSSELL CLAPP, 0F EVANSTON, ILLINOIS.

AEROPLANE.

Specification of Letters Patent.

Patented Get. 19, 1915.

Application filed August 16, 1911. Serial N 0. 644,413.

State of Illinois, have invented certain new and useful Improvements in Aeroplanes, of which the following is a specification.

My invention relates to improvements in aeroplanes and more particularly to means for obtaining longitudinal and lateral stability of an aeroplane during flight.

It is a matter of common knowledge to those skilled in the art of aviation that the center of upward pressure or lift of a plane moves from its gravity or geometrical center toward its forward or entering edge, its precise position being generally somewhere in the front third of a rectangular shaped plane, depending, of course, upon the speed at which the aeroplane is traveling and on the angle of incidence of the plane. As an aeroplane is driven forwardby its propelling mechanism, the center of upward pressure or lift of the plane moves from the geometrical center of the plane toward its entering edge as the speed-increases; it being understood that the angle of incidence of the plane is such that the plane is traveling in a substantially parallel direction relative to the earths surface, or at right angles to the gravity attraction.

As the speed or the angle of incidence varies, so does the point of upward pressure move relative to the geometrical center of the plane. A quick variation in speed frequently caused by suddenly encountering excessive air pressure, or running into a pocket or hole in the air as it is sometimes called, shifts the point of upward pressure so rapidly that a torque strain results, upsetting the aeroplane, so that it either plunges downwardly, head first, or is turned upward. into a vertical position and plunges or slides downwardly, tail first.

The primary object of my invention is to so construct the plane or planes that the point of upward pressure or lift will always come at substantially the geometrical or gravity center. By thus constructing the plane the machine will always right itself into a horizontal position relative to the earths surface under all conditions, as the torque strain referred to above can not occur to upset the machine longitudinally in either direction.

I also obtain lateral stability. to a large extent by constructing my plane as herein shown and described in combination with a suitable steering plane or planes.

These ends are accomplished by so form ing the entering edge of the plane surface that 1t extends as far in the rear of the geometrical center, or center of gravity, of the plane as it does in front, so that a slight shift in the point of upward pressure on my plane has as much effect upon the rear as upon the forward part, resulting in a balancing of the plane longitudinally.

My invention further resides in my particular form of plane whereby I' am able to so distribute the weight of the propelling mechanism as to bring the same at substantially the geometrical center of the plane.

Further objects of the invention will more fully appear in the more detailed description, while the preferred form of aeroplane is shown in the accompanying drawings in which,

Figure l is a top plan view of my improved aeroplane; Fig. 2 is a side elevational view of Fig. 1; Fig. 3 is a front elevational view of Fig. 1; Fig. 4 is a perspective view of Fig. 1.

Referring now more particularly to the drawings, my improved aeroplane is shown in the preferred forms consisting of two planes 5 and 6 constructed of suitable framework and with any desired covering therefor and so designed as to ha an irregular shaped entering edge whereby equal portions of the entering edge are upon opposite sides of the transverse center or gravity line of each plane. This I accomplish in the preferred form by making each plane in the form of a multiple V, the apex of each V extending forwardly in the line of direction of motion.

In my preferred form of construction I preferably arrange one of the planes a little forward of the other plane so that greater projected plane area is obtained. In addition to obtaining a greater projected area the staggered arrangement of the planes, with the lower plane in advance of the upper plane, prevents the aeroplane from falling backward or straight down parallel to the earth, for the following reason: The greater part of the weight of the aeroplane consists of the aviator, engine and fuel tanks, all placed on the level of, or a little above the lower plane. For this reason the center of gyration of the aeroplane about a two super-imposed planes are used the samerighting effect will be secured by staggering the planes and locating the center of mass below the geometrical center of the planes- These planes are connected by suitable braces and tie-rods well known in the art; Disposed longitudinally relative to the direction of motion to the planes, I attach a tail-piece 7 near the end of which I secure theusuel steering. planes 8 and 9 for lateral and vertical guidance, respectively.

V In: my preferred form I secure tilting flaps '10 which may be suitably controlled by theop'erator for obtaining lateral balance if necessary. I. preferably incline the planes slightly rearwardly so that the front or entering edges 11 of each plane are at a little greater elevation than the rear edges 12-. Where two planes are used as shown in the drawing, the outer ends 13 of the lower plane are inclined upwardly at a dihedral angle, affording aslight vertical surface in turning. It will be noted that the entering edge; of each plane; is irregular, as shown in the multiple V' construction, bringing the geometrical center or center of gravity of the aeroplane,as shown, at substantially the .point at which the engine 14 is located,

thereby obtaining equal entering edge both forwardly of and rearwardly of the lateral geometricalcenter line of the planes relative to the direction of motion of the planes.

I also obtain equal entering edge and equal plane surfaces upon opposite sides of the longitudinal center line of the planes relative to its direction of motion.

By reason of this irregular construction of my entering edge, with equal sustaining surfaces on opposite sides of the geometrical center, the center of lift or upward pressure always comes at substantially the geometrical center of the planes when more than one plane is used, and at the geometrical center of a single plane,'so that variations in wind pressure do not change thecenter of application of the lift or upward pressure upon my planes to any great extent, and, if to any ex- Copies of this patent may be obtained for tent, the shifting of the center of ressure from the geometrical center is so slight one way or the other that it results in a torque strain tending to tip the planes either up or'down as the center of pressure may be, but this torque strain is immediately counterbalanced by the large extent of longitudinal plane surface. By so constructin my planes with an irregular entering edge, am able to locate the engine 14 at substantially the geometrical center, and this is equally true of the operators position, thereby bringing the operator in the rear of the engine and centering the weight at the geometrical center, which is highly desirable.

I am also able to place one or more propellers 15 within one of the pockets formed by the irregular or V construction of the plane edges, thereby protecting the propellers to a large extent.

There are, of course, many other minor features to my aeroplane as herein shown, but which need not be described, as the gist of the invention does not reside in details of construction but in the broad idea of so constructing a plane or planes as to bring the center of gravity of the plane and the center of upward pressure substantially coincident, whereby both longitudinal stability and lateral stability is inherent in the structure.

Therefore, without limiting myself to the particular plane construction and mechanism herein shown,I claim:

. 1. An aeroplane having a plurality of continuous planes arranged one above the other, each plane being slightly in advance of the plane above and each plane having its entering edge both in front and in rear of its transverse geometrical center line.

2. An aeroplane having a sustaining plane of multiple V-shape, said plane having substantially equal portions of its entering edge on opposite sides of its transverse geometrical center line relative to its direction of motion.

- 3. An aeroplane having a plurality of sustaining planes each of multiple V-shape and each arranged slightly in advance of the plane above.

4. An aeroplane having a plurality of sustaining planes each of multiple V-shape and each arranged slightly in advance of the plane above, and each plane having its entering edge both in front and 1n rear of its transverse geometrical center line.

CHARLES RUSSELL CLAPP.

Witnesses:

JAMES R. OFFIELD, SADIE M. RYAN.

five cents each, by addressing the Commissioner 01' Patents, Washington, D. 0. 

